1. Field of the Invention
This invention relates to a method and apparatus for separating bone and meat of an upper half of a poultry carcass, from which legs have been cut off (hereinafter simply referred to as upper half), and an auto-loading system used with the apparatus, wherein tissues such as a tendon, ligament, muscle, envelope and the like around a shoulder joint are cut and breast meat is separated from a bone together with wings in a stable manner and, more particularly, to the method and apparatus, in which the separation can automatically be effected with high flexibility to difference in size of upper halves and with a high recovery rate, and the auto-loading system for upper halves, in which the upper halves are continuously transported to feed a plurality of apparatuses for the separating by the help of as many buffer conveyors each for a temporary stay of an upper half awaiting its turn of loading.
2. Description of the Related Art
Recently, breeding, slaughtering, and processing of carcasses of poultry have been grown up to a large scale in a related industry and a variety of automation has largely been carried out in the growth. In the mean time, cutting-off of legs from a carcass of poultry has still been conducted manually. Methods and apparatuses suitable for the use of deboning of the legs have already been proposed by the same inventors.
Separation of breast meat in an upper half, whose leg portions are removed in a previous process, has also been carried out by manual operation. In such manual operation, there has been arisen problems that separated breast meat and supreme (white meat), which remains between furcula, are subject to damages and thereby to their devaluation as article of commerce. Moreover, an operator necessarily conducts manual operation while palms and fingers contact with meat directly, which makes a managing cost in an hygienic aspect higher and, besides, a direct production cost higher due to a lower recovery rate.
Now, description will given about breast meat 10a. An ideal cut plane 35 exists around shoulder joint 11, as seen from a perspective view in FIGS. 8 and 9. Muscle of the supreme 10b is connected with a humerus, which combines with the glenoid 11b of a shoulder joint 11 combines and on the other hand the breast meat 10a and a wing 12 are connected with the shoulder joint 11 by way of a breast muscle and a brachial muscle respectively. The breast meat 10a is present in an area formed by being surrounded by a scapula 11a, the upper portion of an os coracoideum 13 and a furcula 14.
The shoulder joint 11 is integrated with the head (not shown) 12a of a humerus 12b which fits in the glenoid 11b of the scapula 11a by the help of tissues such as a ligament, tendon, muscle, envelope and the like, said scapula 11a joining with a furcula 14 and os coracoideum 13, as seen from FIG. 9.
As can be seen from the above description, separation of breast meat is conducted after cutting the tissues such as a tendon, ligament, muscle, envelope and the like combined with the scapula 11a and the head 12a of a humerus 12b (hereinafter referred to as shoulder joint cutting). A recovery is affected at a great extent by performance in the shoulder joint cutting, that is, if the position and depth of the shoulder cutting is proper for the size of an upper half, a better recovery is secured.
In order to achieve the purpose, it is necessary to properly set the inserting position and cutting depth of a cutter blade in an area for shoulder joint cutting in response to different sizes of the upper half with flexibility of operation.
Configuration of tendons in tissues which are an object of the shoulder joint cutting has been investigated in regards to their positional relations with sizes of upper halves. The following conclusion has been obtained, as a result of detailed studies on the basis of figures of a skeletal system.
1. In FIGS. 14(A), 14(B) and 14(C), the skeleton of an upper half is shown in a front elevational view as seen from the breast side, side elevational view and rear elevational view and FIGS. 15(A) and, 15(B) are enlarged views of encircled portions designated at D and E, each of which include a shoulder joint, in the FIGS. 14(B) and 14(C).
It can be seen from FIGS. 15(A) and 15(B) that:
a) the heads 11c, 12a of a scapula and humerus are combined with each other by two pairs of tendons (i) and (ii); and PA1 b) a tendon (i) is located outwardly of a tendon (ii), as seen from a rear elevational view of FIG. 15(B), a tendon (ii) is originated at the head 11c of a scapula 11b and extends to the head 12a of a humerus 12b outwardly and obliquely relative thereto, and the tendon (ii) is also originated at the head 11c of a scapula 11b and extends to the head 12a of a humerus downwardly and almost vertically.
2. Next, an inserting position of a cutter blade in a shoulder joint cutting is discussed. As can be seen from FIG. 12, a vertical reference plane Ya is set on the inside of the head 11c of a scapula 11b and a horizontal reference plane Xa is set on the head 12a of a humerus 12b. An inserting position of an obliquely moving cutter blade 116 is at distances of Sa from the vertical reference plane Ya and of Ha from the horizontal plane Xa, wherein these values of Sa and Ha fluctuate only in a span of 2 to 3 mm for all the variations in size of upper halves, which is small enough to be neglected.
In consideration of the above situation, it has been found that the position of the obliquely moving cutter blade 116 can be set at an almost proper position, if location of the vertical reference plane is adjusted according to the size of an upper half as work, while a inserting position of the obliquely moving cutter blade 116 is selected at a constant distance from the vertical reference plane Ya, but a problem is how to adjustably determine a location of the vertical reference plane according to a size of the upper half.
As a further finding, it is required in cutting of tissues around a shoulder joint that the two pairs of tendons (i) and (ii) are cut, as described in 1 a), that cutting of tendons (i) is conducted obliquely from an external position in the air, as described in 2 b), and on the other hand, that cutting of tendons (ii) is conducted horizontally.
3. As to a depth of inserting of a cutter blade in cutting the tendons (ii), as can be seen in FIG. 15(B), it has been found that meat is not damaged, even if the edge of the cutting blade is sent till it contacts with the lower portion of the head 11c of a scapula on condition that a direction of the cutter blade is adjusted to be horizontal especially in the last instant of the cutting operation. That is, it has been understood together with the other descriptions of 1 a) and 1 b) that it is only required that two directions of insertion are adopted for a cutting blade and a direction of the cutting blade is required to be horizontal only in the last instant of operation.
Leg portions of a poultry carcass are separated by dividing the carcass at a hip joint and removing spurs and toes and even a skilled worker have been able to debone the legs portions to recover thigh meat at an average rate of 720 leg portions or 360 poultry carcasses per day.
A solution for the above problems has been proposed and tried to automate and rationalize a deboning operation, which is disclosed, for example, in the specification of Japanese Patent Application No. H 4-203528 already filed. According to the specification, a deboning method of poultry suitable for automation and an automated deboning apparatus are disclosed.
The deboning apparatus has, as shown in FIG. 24, a construction that a rotary octagonal table 300 is equipped, processing stations S1 to S8 are located in respective positions of the sides. At the station S1, the tibia 306 of a leg as a work that is shown in FIG. 23, and which has been transported by a conveyor 301, is manually inserted in a chuck (not shown) to fix for deboning. After the chucking, the leg is subjected to various processing, such as extraction by a tool and separating meat by scraping, in given sections F, F, G in the order, from bones, while effecting a first and second cuttings by rotary cutter blades, as shown in FIG. 23, in each of the processing stations S1 to S8 in an automatic fashion with an intermittent feed.
The above mentioned deboning apparatus is also applicable to any form of a cut-up part of poultry, that is to an upper half, which is a processing object of this invention. An auto-loader suitable for such a deboning apparatus has not been proposed in the sense of practical use.